Tire casing vulcanization mold

Abstract

A mold for vulcanizing a tire casing having two beads by direct action of a fluid on the inner walls of the casing, the mold including two crowns for respectively molding the outer surface of each of the beads, each molding crown including, successively and axially from the center of the mold to the outside of the mold, a first annular section having an outer surface supporting the corresponding bead, on shaping of the rough tire casing, and a second annular section for the molding the corresponding head and securing the tightness of the mold.

I claim:  
     
       1. A vulcanization mold for a tire casing having two beads for vulcanization by direct action of a fluid on the inner walls of said casing, said mold comprising two crowns for respectively molding an outer surface of each of the beads, each molding crown successively comprising, axially from the center of the mold to the outside of the mold, a first annular section having an outer surface supporting the corresponding bead, on shaping of a rough tire casing, and a second annular section, axially adjacent and outwardly of said outer surface of said first annular section, for the molding of said bead and securing the tightness of the mold, said second annular section including successively and axially from the center of the mold, a circumferential bearing having a substantially cylindrical surface in contact with the first annular section, a circumferential groove and a truncated cone-shaped portion. 
     
     
       2. A mold according to  claim 1 , in which the cylindrical bearing surface has a diameter (Φ3) greater than the minimum interior diameter (Φ1) of the rough tire casing and the minimum interior diameter (Φ2) of the cured tire casing following vulcanization thereof in the mold. 
     
     
       3. A mold according to  claim 1 , in which each crown has a truncated cone-shaped third section for precentering of the tire casing in the mold, situated in the axial extension of the first section toward the center of the mold. 
     
     
       4. A mold according to  claim 3 , in which the truncated cone-shaped third section has a generatrix forming an angle (α) of approximately 5° with the axis of the mold. 
     
     
       5. A mold according to  claim 1 , in which the outer surface of the first section is concave. 
     
     
       6. A mold according to  claim 1 , in which the circumferential groove has a depth (h) ranging between 0.5 mm and 4 mm. 
     
     
       7. A mold according to  claim 1 , in which the surface of said crowns is totally airtight.